L Tartaric acid

Tartaric acid [526-83-0] (2,3-dihydroxybutanedioic acid, 2,3-dihydroxysuccinic acid), C H O, is a dihydroxy dicarboxyhc acid with two chiral centers. It exists as the dextro- and levorotatory acid the meso form (which is inactive owing to internal compensation), and the racemic mixture (which is commonly known as racemic acid). The commercial product in the United States is the natural, dextrorotatory form, (R-R, R )-tartaric acid (L(+)-tartaric acid) [87-69-4]. This enantiomer occurs in grapes as its acid potassium salt (cream of tartar). In the fermentation of wine (qv), this salt forms deposits in the vats free crystallized tartaric acid was first obtained from such fermentation residues by Scheele in 1769. 

HOCH2CH2OH, MgS04, PhH, L-tartaric acid, reflux, 20 h. 97% yield. These conditions were optimized for the protection of unsaturated aldehydes to prevent double-bond migration. ... 

Deacetylanisomycin (4) is synthesized using L-tartaric acid (1) as a precursor in 12% overall yield16. The key step is the diastereoselective addition of (4-methoxybenzyl)magnesium chloride to the C — N double bond of nitrone 2 at 0°C in the presence of 1 equivalent of ethylmagncsium-bromide diethyl ether complex in dichloromethane. This procedure affords a chromatograph-ically separable mixture of the hydroxylamines 3 a and 3 b in a diastereomeric ratio [(2R,35,4R)/ (25,35,47 )] 70 30 and 60% yield from 2. 

Various attempts have been made to improve the glass polyalkenoate cement. We have already described (Section 5.9.5) the most important iimovation, the use of (-l-)-tartaric acid to improve setting characteristics (Wilson Crisp, 1976). Before its use was discovered, only one glass. 

Roche carries out asymmetric hydrogenation of a p-keto-ester for a pancreatic lipase inhibitor using their Ru (II) BIHEHP catalyst. For scaling up, Roche decided to use a heterogeneous catalyst, modified Ni /L-tartaric acid with NaBr, since this was economically more attractive. 

In 2006, Wang et al. reported the synthesis of a new camphor-derived disulfonamide ligand based on L-tartaric acid that was employed in similar reactions to those described above, giving rise to enantioselectivities of up to 83% ee by using 5 mol% of catalyst loading (Scheme 3.43). ... 

L-Tartaric acid-derived disulfonamide ligand for additions of ZnEt2 to aldehydes. 

In 1998, Ruiz et al. reported the synthesis of new chiral dithioether ligands based on a pyrrolidine backbone from (+ )-L-tartaric acid. Their corresponding cationic iridium complexes were further evaluated as catalysts for the asymmetric hydrogenation of prochiral dehydroamino acid derivatives and itaconic acid, providing enantioselectivities of up to 68% ee, as shown in Scheme 8.18. 

C. (1S,2S)-(-)- and (1 R,2R)-(+)-1,2-Diphenyi-1,2-ethylenediamine (Note 11). A 1 -L, round-bottomed flask equipped with a mechanical stirrer is charged with 42.5 g (0.200 mol) of the racemic diamine and 230 mL of ethanol (Note 9). The solids are dissolved by heating the mixture to 70°C whereupon a hot (70°C), homogeneous solution, of 30.0 g (0.200 mol) of (L)-(+)-tartaric acid (Note 12) in 230 mL of ethanol is added (Note 13). The tartrate salts precipitate immediately, and after the mixture is cooled to ambient temperature, the crystals are collected by filtration, washed twice with 60 mL of ethanol, and dried under reduced pressure. The solids are dissolved in 230 mL of boiling water, 230 mL of ethanol is added and the homogeneous solution is allowed to cool slowly to room temperature. The crystals are collected by filtration, washed with 40 mL of ethanol and dried under reduced pressure. The recrystallization procedure is then repeated twice using the same volumes of solvents (230 mL of water and 230 mL of ethanol) to give 23-25 g (63-69%) of the tartrate salt... 

L-Tartaric acid Tartaric acid, L- (8) Butanediolc acid, 2,3-dihydroxy-,... 

Chirality has also been introduced into crown hosts using optically-active functional groups other than bis-/ -naphthol. For example, the crown (233) derived from L-tartaric acid is a chiral host showing much less... 

Biosyntheses of hexuronic acids and L-ascorbic acid in plants and animals are closely related. Hexuronic acids, L-ascorbic acid, and L-tartaric acid (a possible precursor of dihydroxyfumaric acid) commonly occur together in plants. If a rat is given chloretone (an antispasmodic), both L-ascorbic acid and D-glucuronic acid are excreted in increased quantity.244 Unlike humans, rats can synthesize their own vitamin C, and are therefore independent of outside sources. Here, D-glucose and D-galactose can be utilized, but not D-mannose. 

High stereoselective addition of vinylmagnesium bromide to L-tartaric acid-derived nitrone was used as a key step in the synthesis of (+ )-lentiginosine and its structural analogs (653). 

Asymmetrical addition of alkynylzinc reagents to nitrones has been achieved in the presence of L-tartaric acid ester as a chiral additive (665). 

L-aspartic acid L-tartaric acid Diacetone-D-glucose... 

Canali et al.17 reported the use a linear poly(tartrate) ligand in the asymmetric epoxidation of allylic alcohols. Moderate results were obtained. They also reported the use of branched/crosslinked poly(tartrate), which gave moderate to good results in the asymmetric epoxidation of allylic alcohols. As shown in Scheme 4-9, when L-(+)-tartaric acid and 1,8-octanediol are heated... 

Chiral titanium catalyst for asymmetric Diels-Alder reactions. A Japanese group2 recently reported that a chiral titanium reagent (1), prepared in situ from TiCl2(0-f-Pr)2 and the chiral diol 2, derived from L-tartaric acid, in combination... 

A racemic mixture of a base can be resolved by an active acid which is easily available like d or l tartaric acid. A racemic mixture of alcohols is resolved by esterification with an active acid. The recemic aldehydes have been resolved by using optically active hydrazines e.g., d amyl, phenylhydrozine and separating the resulting hydrozones. 

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